83 lines
2.4 KiB
C++
83 lines
2.4 KiB
C++
|
/*!
|
||
|
|
@file
|
||
|
|
Forward declares `boost::hana::remove_at` and `boost::hana::remove_at_c`.
|
||
|
|
|
||
|
|
@copyright Louis Dionne 2013-2016
|
||
|
|
Distributed under the Boost Software License, Version 1.0.
|
||
|
|
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef BOOST_HANA_FWD_REMOVE_AT_HPP
|
||
|
|
#define BOOST_HANA_FWD_REMOVE_AT_HPP
|
||
|
|
|
||
|
|
#include <boost/hana/config.hpp>
|
||
|
|
#include <boost/hana/core/when.hpp>
|
||
|
|
|
||
|
|
#include <cstddef>
|
||
|
|
|
||
|
|
|
||
|
|
BOOST_HANA_NAMESPACE_BEGIN
|
||
|
|
//! Remove the element at a given index from a sequence.
|
||
|
|
//! @ingroup group-Sequence
|
||
|
|
//!
|
||
|
|
//! `remove_at` returns a new sequence identical to the original, except
|
||
|
|
//! that the element at the given index is removed. Specifically,
|
||
|
|
//! `remove_at([x0, ..., xn-1, xn, xn+1, ..., xm], n)` is a new
|
||
|
|
//! sequence equivalent to `[x0, ..., xn-1, xn+1, ..., xm]`.
|
||
|
|
//!
|
||
|
|
//! @note
|
||
|
|
//! The behavior is undefined if the index is out of the bounds of the
|
||
|
|
//! sequence.
|
||
|
|
//!
|
||
|
|
//!
|
||
|
|
//! @param xs
|
||
|
|
//! A sequence from which an element is to be removed.
|
||
|
|
//!
|
||
|
|
//! @param n
|
||
|
|
//! An non-negative `IntegralConstant` representing the index of the
|
||
|
|
//! element to be removed from the sequence. The behavior is undefined
|
||
|
|
//! if that index is not in the bounds of the sequence.
|
||
|
|
//!
|
||
|
|
//!
|
||
|
|
//! Example
|
||
|
|
//! -------
|
||
|
|
//! @include example/remove_at.cpp
|
||
|
|
#ifdef BOOST_HANA_DOXYGEN_INVOKED
|
||
|
|
constexpr auto remove_at = [](auto&& xs, auto const& n) {
|
||
|
|
return tag-dispatched;
|
||
|
|
};
|
||
|
|
#else
|
||
|
|
template <typename S, typename = void>
|
||
|
|
struct remove_at_impl : remove_at_impl<S, when<true>> { };
|
||
|
|
|
||
|
|
struct remove_at_t {
|
||
|
|
template <typename Xs, typename N>
|
||
|
|
constexpr auto operator()(Xs&& xs, N const& n) const;
|
||
|
|
};
|
||
|
|
|
||
|
|
constexpr remove_at_t remove_at{};
|
||
|
|
#endif
|
||
|
|
|
||
|
|
//! Equivalent to `remove_at`; provided for convenience.
|
||
|
|
//! @ingroup group-Sequence
|
||
|
|
//!
|
||
|
|
//!
|
||
|
|
//! Example
|
||
|
|
//! -------
|
||
|
|
//! @include example/remove_at_c.cpp
|
||
|
|
#ifdef BOOST_HANA_DOXYGEN_INVOKED
|
||
|
|
template <std::size_t n>
|
||
|
|
constexpr auto remove_at_c = [](auto&& xs) {
|
||
|
|
return hana::remove_at(forwarded(xs), hana::size_c<n>);
|
||
|
|
};
|
||
|
|
#else
|
||
|
|
template <std::size_t n>
|
||
|
|
struct remove_at_c_t;
|
||
|
|
|
||
|
|
template <std::size_t n>
|
||
|
|
constexpr remove_at_c_t<n> remove_at_c{};
|
||
|
|
#endif
|
||
|
|
BOOST_HANA_NAMESPACE_END
|
||
|
|
|
||
|
|
#endif // !BOOST_HANA_FWD_REMOVE_AT_HPP
|